In numerous industrial applications, beams of radiant energy are utilized for treating or processing materials. It is often necessary to align these beams so that they will impinge at desired predetermined locations on the workpiece. For example, if a beam of light from a laser used to punch a hole in a piece of paper, the beam must impinge on the paper at the desired location to form the hole at the desired location.
Ordinarily, the beam is aligned with the workpiece by aligning the workpiece with the structure of the treatment apparatus and also aligning the beam with such structure. If the optical path along which the beam is routed in the apparatus includes delicate optical elements such as beam splitters, mirrors, lenses and the like, the beam may become misaligned with the structure of the apparatus, and the alignment of the beam with the structure may require periodic readjustment. The alignment between the beam and the structure must be checked for deviation from the desired alignment. If such deviation is detected, the orientation of the beam must be altered to eliminate it and the alignment of the beam with the structure is then normally rechecked to assure that the proper alignment has been achieved.